Feed leg control device



June 24, 1969 M. WORMAN 3,451,425

FEED LEG CONTROL DEVICE Filed Aug. 8, 1966 INVENTOR. MART/N WORMA/V States Patent Ofiice 3,451,425 Patented June 24, 1969 3,451,425 FEED LEG CONTROL DEVICE Martin Worman, Phillipsburg, N.J., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Aug. 8, 1966, Ser. No. 571,125 Int. Cl. F16k 11/18, 11/20 U.S. Cl. 137-596.2 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a control for feed legs of rock drills and in particular a control for feed legs of stoper type rock drills. In certain applications, the feed leg control of this invention may be used on other types of rock drills.

In some prior feed leg control devices for stoper drills, the air from the drill throttle valve as ported directly to the feed leg at line pressure. The pressure in the feed leg is then adujsted by bleeding air from the leg by an independent valve. When it is desired to drop the drill from the work base quickly, a push button bleeds the feed leg at a rate equal to the rate at which air is supplied. Because the supply air still enters the feed leg at the constant rate, the drill drops slowly.

It is, therefore, the principal object of this invention to provide a novel feed leg control valve which allows the drill to be dropped quickly.

It is another object of this invention to provide a novel feed leg control for a stoper drill which allows metering of the feed leg air before it enters the feed leg.

In general, these objects are carried out 'by providing a control for the feed leg of a rock drill which includes a main body having a fluid inlet passage and a fluid outlet passage for conducting fluid under pressure to said feed leg. A valve is mounted within the main body for regulating the flow of fluid between the inlet and outlet passages. Means are slida-bly mounted within the valve body for blocking the inlet passage and exhausting the outlet passage and the feed leg to atmosphere for lowering the rock drill.

The aforementioned and other objects will become apparent from the following description and drawings in which:

FIG. 1 is a plan view of a stoper type rock drill embodying this invention;

FIG. 2 is a longitudinal section of an embodiment of this invention;

FIG. 3 is a transverse section taken on the line 33 of FIG. 2 in the direction of the arrows;

FIG. 4 is a transverse section taken on the line 44 of FIG. 2 in the direction of the arrows;

FIG. 5 is a fragmentary view on an enlarged scale of a portion of FIG. 2 showing the control of this invention in a lowering position; and

FIG. 6 is a transverse section taken on the line 66 of FIG. 5 in the direction of the arrows.

Referring to FIG. 1 there is shown a rock drill 1 of the stoper type including a front head 2 for holding a drill steel 3 and a bit 4. The drill is suported by a feed leg 5 of a common type and a ground engaging member 6. Air

is supplied to the rock drill from a supply line 7. A control valve 10 is used for raising and lowering the rock drill as the drilling operation continues by acting on a piston in the feed leg. The rock drill and feed leg are well known and, by themselves, do not form a part of this invention.

Referring now to FIG. 2 and the novel features of this invention, the control 10 includes a main body 11 which is secured to the drill 1 by a washer 13 and nut 14. A sleeve 12 having a pair of ports may be used to insure a proper fit. The main body 11 has a fluid inlet passage 40 to receive feed leg supply air and a fluid outlet passage 42 connected to the feed leg to supply the feed leg with air. The outlet passage 42 is counterbored at 47 to receive a feed leg control valve 30. This feed leg control valve has a pair of ports 33 and 35 radially spaced from each other, each having metering grooves 34 and 36, respectively. The valve inlet port 33 is adapted to be selectively aligned with a passage 41 in the main body which, in turn, communicates with the inlet passage 40. The first valve exhaust is adapted to be selectively aligned with an exhaust port 43 in the main body 11.

The valve 30 is provided with a second valve exhaust port which includes an annular groove 38 towards the rear of the valve, a plurality of ports 37 which connect the groove 38 with a groove 44 and a chamber 45 in the main body 11. The chamber 45 is connected to atmosphere by an exhaust passage 46 in the body 11. The rearward most portion of the valve 30 has a bevel gear 31 for mating with a bevel gear 24 on the upper end of a rotating means 21.

A sleeve 20 is secured to the main body 11 by suitable threads and has a valve actuating or rotating means 21 mounted therein. A feed control knob 22 extends out of the sleeve 20 for ease of operation. A stop pin 23 is provided to limit the amount of rotation of the rotating means 20 and thus the control valve 30.

The valve has an axial passage 32 extending therethrough. This passage is adapted to receive a release valve or blocking means 50. This blocking means includes a drilled out portion 52 to provide a blocking portion 51 and an exhaust port 54 for selectively allowing communication between the outlet passage 42, the chamber 45, through the second valve exhaust port, and thus the exhaust passage 46 and atmosphere. There is a head 56 on the rear end of the plunger 50 which is adapted to be engaged by a button 57 which extends through a bushing 60 to the outside of the control so that it may be depressed by the operator of the drill. The release valve 50 is biased rearwardly by a spring 53. A nylon thread locking ring 61 is provided to prevent the bushing 60 from coming unscrewed.

Operation When it is desired to raise the feed leg and thus the rock drill as when drilling is progressing, the handle 22 is positioned so that the port 33 is aligned with the passage 41, as shown in FIGS. 1 and 4. Air from the throttling valve of the drill (not shown) is ported through a passage 15 to the inlet passage 40 of the body 11 into the axial passage 32 of the valve 30 by means of the passages 41 and port 33. The air then goes through the axial passage 32, outlet passage 42, and into the conduit 16 to the feed leg. When the valve 30 and port 33 are aligned with the passage 41, as shown in FIGS. 2, 3 and 4, the maximum amount of air is being fed to the feed leg and the drill will be raised at the maximum rate. If the feed control knob 22 is rotated in a clockwise direction, the valve 30 will be rotated in a counterclockwise direction, and the metering grooves 34 and 36 will begin to perform their function. The amount of air moving through the port 33 will be decreased thus decreasing the supply to the outlet passage 42 and the feed leg. At the same time the metering grooves 36 will begin to register with the body exhaust passage 43 allowing a certain amount of the supply air from the inlet passage 40 to be exhausted to atmosphere thereby decreasing the rate at which the drill is raised. Thus, when the passage 41 is aligned with meter groove 34 to the same extent that exhaust passage is aligned with meter groove 36, the feed leg can be virtually held in a fixed position. With this control valve, an extremely fine adjustment of the advancement and retraction of the feed leg can be achieved.

When for some reason it becomes necessary or desirable to lower the drill quickly, the button 57 may be depressed to its fullest extent. The button 57 contacting head 56 forces the release valve 50 inwardly against the spring 53 and the blocking portion 51 serves to block the inlet port 33 of the valve 30 and thus prevent supply air in the inlet passage 40 from reaching the outlet passage 42. At the same time air in the feed leg and outlet passage 42, which communicates with the release valve 50 through drilled out portion 52, enters a plurality of ports 54 in the valve 50, into a groove 38 in the valve 30, through a plurality of passages 37 and into a groove 44 and hence to the chamber 45. From the chamber 45, the fluid in the outlet passage 42 and feed leg 5 is exhausted to atmosphere through the body exhaust passage or port 46. From this it can be seen that supply air is no longer in communication with the feed leg, and the feed leg is exhausted so that the drill will drop quickly by its own weight forcing out any air in the feed leg and will not have to overcome incoming air.

From the foregoing description it is readily apparent that the objects of this invention have been carried out and that a novel feed leg control device has been provided.

It is intended that the foregoing description be merely that of a preferred embodiment and that the invention not be limited in any way except by that which is Within the scope of the appended claims.

I claim:

1. A control for the feed leg of a rock drill comprising:

a main body having a fluid inlet passage and a fluid outlet passage for conducting fluid under pressure to said feed leg;

a valve means mounted within said body for controlling the volume of fluid flow between said inlet and said outlet passages; and means at least partially mounted within said body and operable independently of said valve means for selectively blocking said inlet and exhausting said outlet and feed leg to atmosphere to thereby lower said rock drill.

2. The apparatus of claim 1 wherein said blocking means is a spring biased plunger and further including means for actuating said valve.

3. The apparatus of claim 2 wherein said main body has at least one exhaust passage therein and said plunger has a port therein for connecting said outlet passage and exhaust passage when said inlet passage is blocked.

4. The apparatus of claim 1 wherein said valve has an axial passage therethrough coaxial with said outlet passage and an inlet port connecting said axial valve passage and said inlet passage.

5. The apparatus of claim 4 further including means for rotating said valve for regulating the flow of fluid between said inlet and outlet passages.

6. The apparatus of claim 5 wherein said blocking means is a spring biased plunger connected to the outside of said main body and slidably mounted with said axial valve passage for blocking said valve inlet port, said main body having an exhaust passage therein, said valve has an exhaust port therein and said blocking means has an exhaust port therein for conducting fluid in said outlet passage and feed leg through said valve exhaust port and to said body exhaust passage and atmosphere.

7. The apparatus of claim 1 wherein said main body has a pair of exhaust passages therein and said valve has an inlet port and a first exhaust port therethrough radially spaced from each other, said valve inlet port being adapted to selectively communicate with said inlet passage and said first valve exhaust port adapted to selectively communicate with one of said body exhaust ports.

8. The apparatus of claim 7 wherein said valve has a second exhaust port connecting said axial valve passage and the other of said body exhaust ports and said blocking means has a port therein for connecting said axial valve passage with said second valve exhaust port when said blocking means is actuated.

9. The apparatus of claim 7 wherein said valve inlet port and said first valve exhaust port have metering grooves adjacent thereto.

References Cited UNITED STATES PATENTS 2,202,216 5/1940 Madsen 137625.l7 XR 2,655,167 10/1953 Dunkelow 137625.17 XR 3,326,240 6/1967 McConnaughay 137-6374 ROBERT W. JENKINS, Primary Examiner.

R. 1. SMITH, Assistant Examiner.

US. Cl. X.R. 137-625.24 

